The present invention relates generally to liquid crystal light valve projectors, and more particularly, an improved color beamsplitter cube and liquid crystal light valve projector employing the color beamsplitter cube.
The assignee of the present invention designs and develops liquid crystal light valve projectors. As part of this effort, a stacked X-cube color beamsplitter has been developed for use in certain of the liquid crystal light valve projectors. Stacked X-cube color beamsplitters are generally discussed in a publication by Technology J. A. Fowler and R. Blanchard in 912.SID92 Digest, in a paper entitled "Avionics Display using LCD Projection".
The stacked X-cube color beamsplitter employs eight prisms that are arranged in two stacked groups of four prisms each that separately process incident white light to divide the incident white light into three primary colors, and combine the divided primary colors to produce white light that is projected. More specifically, the stacked X-cube color beamsplitter requires eight right angle prisms that are cemented to two cubes of four prisms each.
This stacked X-cube color beamsplitter is relatively costly to produce because of the relatively large number of optical elements that are used therein. Furthermore, a considerable amount of time is required to cement the prisms together to fabricate the cube. The amount of mounting hardware that is needed to assemble the prisms into the cube is also greater than is desired.
Accordingly, it is an objective of the present invention to provide for an improved color beamsplitter cube and liquid crystal light valve projector employing the color beamsplitter cube.